Hamad I. Odhabi Ray J. Paul Robert D. Macredie The Four Phase Method for Modelling Complex Systems. 510-517 1997 conf/wsc/1997 WSC https://doi.ieeecomputersociety.org/10.1109/WSC.1997.640912 https://doi.org/10.1145/268437.268557 db/conf/wsc/wsc1997.html#OdhabiPM97